Fahey/Insel/Roth, Fit & Well: Core Concepts and Labs in Physical Fitness and Wellness, Chapter 6 © McGraw-Hill Higher Education Body Composition Chapter

Fahey/Insel/Roth, Fit & Well: Core Concepts and Labs in Physical Fitness and Wellness, Chapter 6© McGraw-Hill Higher Education

Body Composition

Chapter 6


What Is Body Composition? Body composition = the body’s

relative amounts of fat mass and fat-free mass (bone, water, muscle, connective and organ tissues, teeth)

Essential fat = crucial for normal body functioning 3–5% of total body weight in males 8–12% of total body weight in females

Nonessential fat = adipose tissue


Typical Body Composition


Overweight and Obesity The most important consideration in

evaluating body weight and composition is the proportion of total body weight that is fat (percent body fat)

Overweight = total body weight above a recommended range for good health

Obesity = severely overweight and overfat; characterized by excessive accumulation of body fat


Prevalence of Overweight and Obesity


Obesity Trends* Among U.S. Adults1990

No Data <10% 10%–14%

(*BMI ≥30, or ~ 30 lbs overweight for 5’ 4” woman)

Source: Behavioral Risk Factor Surveillance System, CDC


Source: Behavioral Risk Factor Surveillance System, CDC

(*BMI 30, or ~ 30 lbs overweight for 5’4” person)

No Data <10% 10%–14% 15%–19% 20%–24% ≥25%

(*BMI ≥30, or ~ 30 lbs overweight for 5’ 4” woman)

Obesity Trends* Among U.S. Adults2002


Excess Body Fat and Wellness

Increased risk of chronic disease and premature death; associated health problems include Unhealthy blood fat levels Impaired heart function Heart disease and hypertension Cancer Impaired immune function Gallbladder disease Kidney disease Skin problems Sleeping problems


Body Composition and Cancer Mortality


Body Composition and Diabetes Obese people are more than three

times as likely as nonobese people to develop diabetes

Excess body fat is a key risk factor for the most common type of diabetes


Diabetes Diabetes mellitus = disruption of

normal glucose metabolism Type 1 diabetes = the pancreas produces

little or no insulin Type 2 diabetes = the pancreas doesn’t

produce enough insulin, cells are resistant to insulin, or both

Gestational diabetes = develops in 2–5% of pregnant women

Pre-diabetes = elevated blood glucose levels


Diabetes


Diabetes: Symptoms


Diabetes: Prevention Regular physical activity including

endurance exercise and weight training

Moderate diet rich in whole grains, fruits, vegetables, legumes, fish, and poultry

Modest weight loss For people with pre-diabetes, lifestyle

changes are more effective than medication in preventing diabetes


Diabetes: Treatment Keep blood sugar levels within safe

limits through diet, exercise, and, if needed, medication

Monitor blood sugar levels with a home test

Lose weight if overweight


Body Fat Distribution and Chronic Disease Location of fat is important to health

People who gain weight in the abdominal area = “apples;” this group has an increased risk of coronary heart disease, high blood pressure, diabetes, and stroke

People who gain weight in the hip area= “pears”


Physical Activity, Overweight, and Risk of Death


Body Composition and Wellness Excess body fat decreases the

ability to perform physical activities Unrealistic expectations about body

composition can hurt self-image; exercise improves body image

Set a realistic goal and maintain a wellness lifestyle to develop a healthy body composition


Problems Associated with Very Low Levels of Body Fat Too little body fat is associated with

reproductive, circulatory, and immune system disorders Less than 10–12% for women Less than 5% for men


Female Athlete Triad A condition consisting of three

interrelated disorders


Body Mass Index A rough assessment based on the

concept that a person’s weight should be proportional to height

Body weight in kilograms is divided by the square of height in meters

Elevated BMI is linked to increased risk of disease, especially if associated with large waist circumference


Body Mass Index


Body Mass Index and Risk of Type 2 Diabetes


Estimating Percent Body Fat Skinfold measurements:

Folds of skin are measured with a caliper. The measurements are used in equations that link the thickness of skinfolds to percent body fat calculations made from more precise experiments.


Estimating Percent Body Fat Underwater weighing: An individual is

submerged and weighed under water. Percentages of fat and fat-free weight are calculated from body density.

The Bod Pod: The amount of air displaced by a person in a small chamber is measured by computerized sensors.

Bioelectrical impedance analysis (BIA): A small electrical current is sent through the body, and the resistance of the body to it is recorded. The resulting estimates of how much water is in the body can be used to determine body composition.


Assessing Body Fat Distribution Disease risk increases with total waist

measurement of more than 40 inches for men 35 inches for women

Disease risk increases with total waist-to-hip measurement above 0.94 for young men 0.82 for young women


Setting Body Composition Goals If fat loss would benefit your health, set a

realistic goal in terms of percent body fat or BMI

If you have underlying health issues, check with your physician before setting a goal

A little weight loss at a time can be very beneficial; focus on a healthy lifestyle including proper diet and exercise


Making Changes in Body Composition

Lifestyle should focus on: Regular physical activity, endurance exercise,

and strength training


Making Changes in Body Composition Lifestyle should focus on:

Moderate energy intake Physical activity is the key to long-term

success

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Fahey/Insel/Roth, Fit & Well: Core Concepts and Labs in Physical Fitness and Wellness, Chapter 6 © McGraw-Hill Higher Education Body Composition Chapter